The following relates generally to multi-layer memory arrays and more specifically to self-aligned memory decks in cross-point memory arrays in which N memory decks may use N+1 patterning and etch operations.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary devices have two states, often denoted by a logic “1” or a logic “0.” In other systems, more than two states may be stored. To access the stored information, a component of the electronic device may read, or sense, the stored state in the memory device. To store information, a component of the electronic device may write, or program, the state in the memory device.
Multiple types of memory devices exist, including magnetic hard disks, random access memory (RAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), read only memory (ROM), flash memory, phase change memory (PCM), and others. Memory devices may be volatile or non-volatile. Non-volatile memory, e.g., flash memories or FeRAM, may maintain their stored logic state for extended periods of time even in the absence of an external power source. Volatile memory devices, e.g., DRAM, may lose their stored state over time unless they are periodically refreshed by an external power source. Improving memory devices may include increasing memory cell density, increasing read/write speeds, increasing reliability, increasing data retention, reducing power consumption, or reducing manufacturing costs, among other metrics. Some types of memory devices may use variations in resistance or voltage drop across a cell to program and sense different logic states. For example, self-selecting memory may leverage ion migration properties in a cell.
Fabricating a memory device may include forming, patterning, and removing material according to patterns that define portions of the memory device. Fabrication is generally performed in clean rooms using highly specialized fabrication equipment, and fabrication facilities are often referred to as “wafer fabs” or “semiconductor fabs.” Such fabrication facilities and associated equipment require substantial capital investment, and thus efficient manufacturing may enhance the throughput and utilization of such facilities.